I have a 2002 WJ 4.0L and I was cleaning my throttle body so I decided to replace my Idle Air Control Valve. The replacement came with the O ring that seats it in the housing, but the housing connects to the throttle body and it needs a gasket. I cannot for the life of me find one! One came off of it when I cleaned it and I can't find anywhere that says it exists, not even Mopar parts sites. Does the housing that holds the Idle Air Control Valve to the throttle body need a gasket? Usually all metal to metal parts that transfer liquid use one, but since it's just air maybe it doesn't need one? Someone please confirm I am or am not going crazy hahaha.

 

I think it needs the gasket because it needs vacuum. Just get an air conditioner o-ring.

 

You can make your own flange gasket with the same material as OEM from an auto supply. Try to match the original gasket thickness as closely as possible (if original is lost then look it up or refer to that of a friend's IAC). Just trace the shapes on paper to form a stencil then use that as your guide to cut the gasket material in the needed shape/pattern. Install a dry gasket on a clean/smooth flange mating surface. Don't use any spray/adhesive in this application.